# Communities Visualization Functions
# Reference: https://graphsandnetworks.com/community-detection-using-networkx/
def set_node_community(G, communities):
'''Add community to node attributes'''
for c, v_c in enumerate(communities):
for v in v_c:
# Add 1 to save 0 for external edges
G.nodes[v]['community'] = c + 1
def set_edge_community(G):
'''Find internal edges and add their community to their attributes'''
for v, w, in G.edges:
if G.nodes[v]['community'] == G.nodes[w]['community']:
# Internal edge, mark with community
G.edges[v, w]['community'] = G.nodes[v]['community']
else:
# External edge, mark as 0
G.edges[v, w]['community'] = 0
def get_color(i, r_off=1, g_off=1, b_off=1):
'''Assign a color to a vertex.'''
r0, g0, b0 = 0, 0, 0
n = 16
low, high = 0.1, 0.9
span = high - low
r = low + span * (((i + r_off) * 3) % n) / (n - 1)
g = low + span * (((i + g_off) * 5) % n) / (n - 1)
b = low + span * (((i + b_off) * 7) % n) / (n - 1)
return (r, g, b)
def draw_communities(G, communities):
plt.rcParams.update(plt.rcParamsDefault)
plt.rcParams.update({'figure.figsize': (15, 10)})
plt.style.use('dark_background')
# Set node and edge communities
set_node_community(G, communities)
set_edge_community(G)
# Set community color for internal edges
external = [(v, w) for v, w in G.edges if G.edges[v, w]['community'] == 0]
internal = [(v, w) for v, w in G.edges if G.edges[v, w]['community'] > 0]
internal_color = ["black" for e in internal]
node_color = [get_color(G.nodes[v]['community']) for v in G.nodes]
# external edges
nx.draw_networkx(
G,
pos=pos,
node_size=0,
edgelist=external,
edge_color="silver",
node_color=node_color,
alpha=0.2,
with_labels=False)
# internal edges
nx.draw_networkx(
G, pos=pos,
edgelist=internal,
edge_color=internal_color,
node_color=node_color,
alpha=0.05,
with_labels=False)
plt.show()
